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Old 11-30-2020, 07:48 AM   #21
nkaminar
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Default Re: Black spark plug ooze

As others have suggested, the plug gaskets are leaking. The engine is pumping oil past the rings so if the engine is not newly rebuilt then the rings are worn. A knock means the bearings need tightening. If you are not mechanically competent, then you either need to study up or find someone who is. My advice would be to take the engine out of the car and work on it on an engine stand. The work can be done in the car but it is easier if you can just turn the engine over to work on the bearings. Take the head off and see if you can move the pistons in the cylinders when they are near the top. If you can then you need an overhaul. If not then you can get by with new rings. The bearings can be tightened up by taking one or more shims out. Of course the cylinders and crank journals have to be examined for scoring.

The oil may also be coming from worn valve guides allowing oil to suck up through the guides. While you have the head off you can check this by moving the valves when they are up. If you can move them then you need new guides and maybe valves.

If the journals look worn you will have to take the crank out to measure them. If out of round or tapered than the crank will have to be reground.

While you are at it check everything else, like the clutch and cam gear.

Good luck.
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Old 11-30-2020, 11:26 AM   #22
doug.nichols
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Default Re: Black spark plug ooze

Not a high compression head.
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Old 11-30-2020, 12:11 PM   #23
Bob C
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Default Re: Black spark plug ooze

Quote:
Originally Posted by doug.nichols View Post
1crosscut: I am running electronic ignition.

It looks like you still have to advance it by hand, isn't the arrow pointing
to the advance rod?
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File Type: jpg Plugs leakage 1.jpg (37.3 KB, 46 views)
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Old 12-01-2020, 10:51 PM   #24
SteveR.
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Default Re: Black spark plug ooze

On my just-overhauled engine I had a plug leaking like this. I added anti-seize to the plug threads and I believe that has stopped the leaking. Now I'm wondering if I have a ring issue...guess I need to look at the plugs as well as watch for oil consumption. The engine has around 200 miles on it.
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Old 12-02-2020, 07:02 AM   #25
nkaminar
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Default Re: Black spark plug ooze

Steve R,

It will take about 1,000 miles or more before your engine is broken in. It needs to build a shine on the cylinder walls. Cast iron has the ability to do that because of all the carbon in the metal. The engine will pump some oil before it is broken in completely. Take it easy during the break in period and you will be rewarded by a good running engine.

Anti-seize is a good idea for the plug threads regardless of leakage or not. It will save you form having a seized plug.
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A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
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Old 12-02-2020, 08:27 AM   #26
Jack Shaft
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Default Re: Black spark plug ooze

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On an older engine to 'force' the rings to work one method is to find a nice quiet stretch of road and accelerate to full speed in 2nd gear then full decelerate, remove you foot from the pedal, this puts force against the rings in two directions. Do this on a fully warmed up engine, repeat for a half an hour or so.
Assembled a lot of engines in my career, from 3616 Cat haul truck engines (pistons the size of gallon paint cans,16 of them) to lawnmowers. I've found that operating a correctly assembled engine normally is the best break in method, along with a close regimen of oil changes to remove metal and assembly debris.
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Old 12-02-2020, 09:31 PM   #27
noboD
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Default Re: Black spark plug ooze

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Originally Posted by nkaminar View Post


Anti-seize is a good idea for the plug threads regardless of leakage or not. It will save you form having a seized plug.
I think almost every shop manual I have ever seen says NOT to do this. It is also something I have done to every spark plug I have installed for over 50 years, especially aluminum heads with no inserts.
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